Method for electronic control and adjustment of the movement of electrically actuated units

ABSTRACT

There is a method for controlling the movement of electrically operated assemblies, more particularly of window lifters, sliding roofs or the like in motor vehicles. The assembly has a setting device is connected to a drive device. At least in one partial area of the displacement path, the displacement force is restricted to a predetermined maximum value. A parameter is proportional to the displacement force of the electrically operated assembly. Upon reaching a boundary value corresponding to the maximum value of the displacement force over a predetermined time span, the parameter is regulated to a value corresponding to this boundary value.

FIELD OF THE INVENTION

The invention relates to a method for controlling and regulating themovement of electrically operated assemblies, more particularly windowlifters, sun roofs or the like in motor vehicles.

BACKGROUND OF THE INVENTION

From DE 30 34 118 A1 a method is known for electronically operating andmonitoring the opening and closing cycle of electrically operatedassemblies, such as window lifters and electric sun roofs in motorvehicles. The path covered during opening of the assembly iselectronically captured. During closing of the assembly, the capturedopening path is compared electronically with the closing path which hasbeen covered. The opening and closing path of the assembly is, for thispurpose, divided up into three areas of which the first area runs fromhalf opened to fully opened, the second area runs from half opened topractically fully closed and the third area runs from practically fullyclosed to completely closed.

In the first and third areas, the blocked state, which represents thefully opened and fully closed assembly, is detected and a setting memberof the assembly is switched off. In the second area, the speed of aservo drive of the assembly is detected and, in the event of a reductionin the speed, the servo drive is switched off.

With this known method for producing a so-called “antijam protection,”the servo drive is designed with regard to its power so that themechanical resistances which are conditioned by the type of assembly andthrough outside influences are overcome over the entire displacementarea. For this reason, the servo drive is designed with its power outputsignificantly greater than is necessary for most of the displacementrange. This in turn has the result that a part of the body present inthe displacement area is jammed with a very high force by the assemblypart which is being displaced.

A further drawback with this known method is that in the third area,that is as the window pane or sliding roof enters into the seal area forcompletely closing the window or roof, only the blocking state and not,however, an anti-jam state is detected.

From DE 195 07 137 A1, a method is known for monitoring and controllingthe opening and closing process of electrically operated assembliesprovided in motor vehicles. The power of the servo motor is controlledso that the displacement speed of the setting member is adjustable overits displacement path, in dependence on predetermined positions of theassembly. In this way, the force exerted in the jamming state by theassembly part, which is to be displaced, is to be restricted to aminimum over critical areas of the displacement path, so that thecritical area is covered more slowly and thus more sensitively.

This method does indeed allow a “soft inlet” into the seal area, that isa slow displacement speed of the assembly part being displaced in thearea of the seal inlet, in order to meet the requirements which arespecific to individual countries with regard to an effective anti-jamprotection. The slow inlet of the assembly part being displaced into theseal area, however, makes it difficult to almost impossible to recognizea standardized 4 mm round tube to determine the efficiency of theanti-jam protection and to safely distinguish the influences of thedisplacement forces in the sealing area. This is particularly true inthe case of frameless doors and doors with panes on the outside.Furthermore, the known method leads to faulty releases of the anti-jamprotection with subsequent reversing of the assembly being displacedduring entry into the seal. Furthermore, the closing time of the windowis increased.

From DE 35 32 078 C2, a control method is known for controlling thedrive of windows or doors with an electric motor. A drive current ismeasured during the closing movement and the change in power is checkedat constant time intervals by setting a current change boundary value.To this end, a minimum current value is predetermined inside a constantperiod, to which is added a fixed amount and the total sum is set orlaid down as the reference value for detecting an abnormal motor load.If this boundary value is exceeded, then the closing movement isswitched over to an opening movement.

The drawback with this known control method is that likewise temporarydisturbances during a closing movement, which are traced back toexternal influences or temporary heavy going (operational difficulties)of the system, but without a jamming state existing, are substantiallynot recognized and lead to an opening movement although the closingmovement could be continued.

From DE 41 12 998 A1, a method is known for controlling a gate drivewhich has a setting device, a drive device connected with the settingdevice, as well as a control and evaluator electronics for evaluatingmeasuring signals and for producing control commands. To displace a gateoperated by means of the gate drive, a displacement force is applied theamount of which is selected in dependence on the displacement path.

Should the displacement force exceed a predetermined safety limit, thenthe drive device is switched off or the drive device is reversed. Thissafety limit is formed by the sum of the displacement force dependent onthe displacement path and a constant additional force. In this way, itis possible to compensate for interference by environmental or seasonalfactors, without resulting in a premature safety cut-off.

With this known method, interference through environmental or seasonalfactors are indeed taken into consideration, but the drive device isswitched off every time the safety limit is exceeded. Also, here only atemporary disruption, during a closing movement which is due to outsideinfluences or temporary difficulties in the system without a jammingcase existing, is not recognized. This leads to a cut-off or reversion,although the closing movement could be continued.

SUMMARY OF THE INVENTION

The object of the invention is to provide a method of the kind alreadymentioned wherein over the entire displacement area of a setting device,an anti-jam protection is guaranteed. The anti-jam protection satisfieseven the most stringent safety requirements, but rules out, as far aspossible, a faulty reversing or stopping of the setting device based onexternal influences, variable resistances or too little displacementforce in the displacement area.

The solution according to the invention ensures, over the entiredisplacement area of the setting device, an anti-jam protection whichsatisfies the most stringent of safety requirements. At the same time,the anti-jam protection ensures that the setting device opens or closesan electrically operated assembly with sufficient displacement forceindependently of external influences and variable resistances in thedisplacement area, at the discretion of the operator.

Substantially eliminating external influences and different resistancesin the displacement area ensures that even when the electricallyoperated assembly is stationary, despite a predetermined closingimpulse, a regulated closing process takes place over a predeterminedtime interval. In this additional time interval, however, thepredetermined maximum value of the displacement force is not exceededuntil either further movement of the electrically operated assemblytakes place, or in the event of a continued stationary state of theelectrically operated assembly, a drive device is switched off.

Parameters proportional to the displacement force of the electricallyoperated assembly are, for example, the current taken up by the drivedevice of the electrically operated assembly or the torque delivered bythe drive device. Parameters correlated with the dynamics of the settingdevice of the electrically operated assembly are, for example, the speedor acceleration of the displacement device or assembly.

The excess force restriction can be restricted to a partial area of thedisplacement path, since, for example, the jamming of larger parts ofthe body need not be considered when opening the electrically operatedassembly and in the area adjoining the completely opened state of theassembly.

From U.S. Pat. No. 5,410,229, a circuit arrangement for controlling thespeed of an electric motor is known wherein the motor is stopped onreaching a predetermined counter torque. For this purpose, the motorcurrent is controlled in pulse width modulation in dependence on thecaptured speed of the electric motor and a predetermined maximum torque.

However, with this electronic coupling, the motor current is constantlyinterrupted when the predetermined maximum torque is reached, so thatwhen used for an electrically operated assembly in motor vehicles, aclosing movement would be interrupted. For example, if as a result ofexternal influences the counter torque reaches a corresponding value, awindow pane could not be completely closed. On the other hand, with acorrespondingly high value of the permissible counter torque, aninadmissible jamming force would act on a part of the body located inthe displacement area of the electrically operated assembly, so that theknown control circuit would be unsuitable for the present case.

In DE 196 15 581 A1, which has an earlier priority, a method isdescribed for controlling electrical drives in motor vehicles with anelectric motor whose controlled operation is provided by a torque/speedcharacteristic line and wherein the active torque is monitored. With aboundary torque which is greater than the torque normally occurring andclearly lower than the maximum torque the drive is regulated to anapproximately constant torque.

With this method, first a boundary torque is fixed, that is a staticboundary value is predetermined for the boundary torque. Compared tothis, the present invention claims the provision of a dynamic boundaryvalue which takes into account, by way of adaptation, a slight excessforce. The dynamic boundary value is changeable with each opening orclosing process, so that to produce an anti-jam protection, a smallclamping force of any size is guaranteed without the drive deviceundesirably coming to a standstill as a result of too littledisplacement force in dependence on the displacement path.

The parameter proportional with the displacement force is preferablyregulated upon reaching a predetermined boundary value dependent on thedisplacement position (envelope curve b). The predetermined boundaryvalue corresponds to the maximum excess force permissible at therelevant displacement position.

The boundary value regulation of the parameter proportional with thedisplacement force takes place within the predetermined time span untileither the parameter understeps (or falls below) the predeterminedboundary again, or either the setting device or the drive device hascome to a standstill. The position-dependent regulation of the excessforce thereby takes into account the normal displacement force requiredfor displacing the assembly. As a result, with a correspondingrestriction of the excess force, even in the most unfavorable case, ajamming state always remains in the harmless area.

The interruption of the current delivered to the drive device and/orreversing the rotary direction of the drive device is preferably delayedby a time interval Δt0. The drive device sends out a constant torque tothe setting device during the duration of the delay.

The time interval Δt0 is preferably measured so that a satisfactorydifferentiation can be made between a jamming case and an external,temporary (dynamic) fault.

A further advantageous development of the solution according to theinvention is characterized in that the boundary value of the parameteris increased by a predetermined amount when the setting device or thedrive device has come to a standstill and a control impulse is deliveredwithin the predetermined time span by an operating device, which causesthe electrically operated assembly to be closed.

This development of the solution according to the invention provides anincrease in the drive power in the event that, during the time durationof the boundary value regulation within the predetermined time interval,an increased ideal value is produced when the operating person, despitea standstill of the electrically operated assembly, creates a switchimpulse controlling the closing movement, i.e. wants to carry out aclosing of the electrically operated assembly.

An advantageous development of the solution according to the inventionis characterized in that the parameter corresponds to the currentsupplied to an electric motor as the drive device, so that the currentcollection of the electric motor is restricted to a value whichcorresponds to a maximum resulting excess force.

Restricting the current collection of the electric motor to a valuewhich corresponds to a maximum resulting excess force can take place inthat the maximum value of the current delivered to the electric motor isset at a value corresponding to the maximum resulting excess force or inthe event of a pulse width modulation of the current delivered to theelectric motor, the peak value (maximum value), the arithmetic meanvalue or quadratic mean value (effective value) of the current is set toa value corresponding to the maximum resulting excess force. In anotheralternative, the maximum value, the arithmetic mean value or thequadratic mean value of the current is predetermined depending on theposition of the setting device.

Restricting the current collection of the electric motor to a valuecorresponding to the maximum resulting excess force ensures that thesetting device carries out the desired displacement movement without theforce, which extends beyond the required displacement force, being ableto represent a danger for parts of the body present in the displacementarea in the event of jamming.

From U.S. Pat. No. 5,268,623, a circuit arrangement is known forcontrolling a direct current motor with a current restricting devicewhich governs the direct current motor with current blocks with varyingpulse duration/pulse pause ratio. In the event of a blocking of thedirect current motor, the pulse duration/pulse pause ratio is reduced sothat neither the motor overheats nor does the starting current, at thestart-up of the direct current motor, adopt too high a value.

With this known control method, when the direct current motor isblocked, the current supply to the motor is not interrupted. Thearithmetic mean value of the current supplied to the direct currentmotor in the pulse width modulation is always reduced to a value whichis harmless for the direct current motor when a blocked state occurs,that is any counter torque detected as a blocked state leads to areduction of the motor torque to a fixed value. In the present case, inrelation to the window entering into the seal area with increasedresistance detected as a blocked state, no complete closing of thewindow pane would result.

Compared to this, however, the method according to the inventionguarantees the implementation of the desired displacement path thatdepends on different resistances or counter torques appearing in thedisplacement path, because there is always an excess force. The excessforce is a force which exceeds the force required for the displacementmovement by a predetermined amount. The amount of the excess force canthereby remain constant over the entire displacement path, when thedrive force required for the displacement movement is adapted to thedisplacement resistances over the displacement path. This excess forceis measured so that it satisfies at any location in the displacementpath the most stringent anti-jam protection requirements so that, evenin critical areas, both the completion of the desired displacementmovement and an effective anti-jam protection are guaranteed.

The displacement force and/or the excess force can, according to afeature of the method according to the invention, be predetermined independence on the motor voltage, the motor speed, and/or the motortemperature or the surrounding temperature. The detection of thesevalues makes it possible to take into account outside or system-imminentinfluences when implementing a displacement movement by taking intoaccount both the anti-jam protection and also a safe implementation ofthe displacement movement.

The electric motor is preferably classified at a testing station withregard to at least a characteristic feature (e.g. rise or slope in themotor characteristic line). The at least one characteristic feature isused to calculate an envelope curve restricting the excess force.

A particularly advantageous development of the method according to theinvention is characterized in that the motor characteristic line of theelectric motor is recorded over the displacement path of the settingdevice and is stored. An amount of the current corresponding to themaximum resulting excess force is added to the motor current of themotor characteristic line corresponding to the relevant motor torque atthat time. The current delivered to the electric motor is restrictedover the at least one partial area of the displacement path to thisresulting maximum value of the current.

The restriction of the maximum motor torque and thus the restriction ofthe maximum excess force of the electrically operated assembly can takeplace, according to this method feature, by a position-dependent fixingof the maximum value of the current supply to the electric motor. Theposition-dependent maximum value is determined in a defined “measuringstroke.” To this end, the normal curve for the current collection isdetermined through the implementation of a complete displacementmovement in a standardizing run. The relevant maximum value of thecurrent collection or current supply to the electric motor is determinedby taking into account the restricted excess force through an envelopecurve which is calculated by including the various influencing factors.

To these influencing factors belong, for example, the voltage, thespeed, the preliminary resistance, the motor and surrounding temperatureas well as the specific motor characteristic line which is inherent toeach electric motor and which can undergo considerable fluctuations.This motor characteristic line can, where applicable, be individuallydetermined at a motor testing station in production so that fixing themaximum motor current with a sufficient restricted excess force, takinginto account an active antijam protection, can be adapted individuallyto each relevant electric motor.

The resulting or maximum excess force can be adapted selectively, alsoadaptively, to the different resistances in the displacement areathroughout the service life. The current collection of the electricmotor is detected over the displacement area and is stored as a valuepair with the relevant position of the displacement device. In this way,it is possible to detect areas of heavy going in the lift area and/orheavy going in the area of an inlet into the seal and thus to fix,adaptively, the displacement force required for the displacementmovement and the resulting excess force.

A further advantageous development of the solution is characterized inthat the envelope curve restricting the excess force is set high whenthe speed of the electrically operated assembly, after reaching thepredetermined boundary value, is not reduced by the parameter, or thenegative acceleration does not exceed a boundary value. Raising theenvelope curve can thereby take place by a predetermined amount or untilthe speed of the electrically operated assembly has reached a certainvalue.

This further development of the solution according to the inventiontakes into consideration that, as a result of external influences orsystem-conditioned resistances in the displacement area, the parameterwhich is proportional to the displacement force does indeed reach thepredetermined boundary value. However, either the speed of theelectrically operated assembly is not reduced or the braking of thesystem caused by the resistances does not extend beyond a certainamount. This leads to a reduction of the boundary value in order to takeinto account this heavy going caused by the external influences oradditional resistances in the displacement area.

Through the position-related detection of delays (heavy going) of theelectrically operated assembly and storage of the detected values, it ispossible to change the path of the envelope curve adaptively.

A further development of the solution according to the invention ischaracterized in that, upon reaching the predetermined maximum value,the arithmetic mean value or the effective value of the currentcollected by the electric motor, the current delivered to the electricmotor is interrupted and/or the rotary direction of the electric motoris reversed.

If, according to this feature of the method according to the invention,the motor current reaches the fixed or calculated maximum value, themotor current is restricted and kept constant. This development of thesolution according to the invention always proves expedient when areliable differentiation between areas of heavy going action, forexample, when entering into the seal, and a jammed state is notpossible. Since the excess force, in the case of a restricted currentwhich is kept constant is, however, always less than a predeterminedboundary value, the risk of a part of the body becoming jammed does notarise even in the most unfavorable cases.

According to a further development of the method according to theinvention, after reaching the fixed or calculated maximum value of themotor current, an immediate or time-delayed reversal of the displacementdevice can take place. In particular, the time-delayed reverse serves toscreen out dynamic disruptions which appear, for example, as a result ofshort-term negative accelerations through potholes or short-termdisturbances in the event of a lifting movement of the electricallyoperated assembly.

A constant torque is preferably delivered to the displacement deviceduring the deceleration of the displacement motor.

According to a further feature of the method according to the invention,the rise in the motor torque can be delayed so that the excess force ofthe electrically operated assembly only rises slowly. A restriction ofthe motor current rise (di/dt) connected therewith can preferably beproduced through a corresponding switch element, such as a rhythmicsemi-conductor, a controllable resistance or the like.

A pulse width control of the motor current, by means of a semiconductorswitch allows the fixed or calculated maximum value of the motor currentto be adapted over the entire displacement area of the electricallyoperated assembly in the shortest possible time and thus in smallposition-change steps. A circuit arrangement of this kind furthermoreensures a simple construction or a simple programming of the controlelectronics taking into account the most varied of influencing factors,which can be additionally detected or taken into account within theframework of an adaptive control.

Since the same current flows through the semiconductor switch as throughthe servo motor, it is also possible to achieve a simple overheatingprotection for the displacement motor, particularly as many known powersemiconductor switches detect the actual operating temperature in orderto prevent a thermal breakdown of the semiconductor switch. Asemiconductor switch without temperature detection, can be coupledthermally, for example, to a temperature-dependent resistor or the like,in order to switch offset semiconductor switch upon reaching a criticaltemperature and thus to interrupt the further supply of current to thedisplacement motor.

Instead of measuring current to regulate the scanning ratio of the pulsewidth modulation, the scanning ratio can be calculated from the idlingspeed, the actual speed and the motor characteristic line of theelectric motor, and thus a device for detecting the motor current can bespared.

BRIEF DESCRIPTION OF THE DRAWINGS

The idea underlying the invention will now be explained in furtherdetail with reference to the embodiment shown in the drawings in which:

FIG. 1 shows a diagrammatic view of various displacement areas in awindow lifter system;

FIG. 2 shows a graphic representation of two different motorcharacteristic lines;

FIG. 3 shows a diagrammatic illustration of a circuit arrangement forcontrolling a window lifter system;

FIG. 4 shows a diagrammatic illustration of the motor current or motortorque versus the displacement path of a window lifter system;

FIG. 5 shows a diagrammatic view of the motor current or motor torqueover the displacement path and over the displacement time with theboundary value regulation registered therein;

FIG. 6 shows a diagrammatic view of a boundary value regulation in theevent of “hard jamming”;

FIG. 7 shows a diagrammatic illustration of the boundary valueregulation in the event of “soft jamming” or heavy going in thedisplacement area;

FIG. 8 shows a diagrammatic view of the boundary value regulation in theevent of a temporary outside influence and

FIG. 9 shows a graph for determining the scanning ratio of a pulse widthmodulation from the idling speed and the actual speed of an electricmotor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The displacement areas shown in FIG. 1 are covered by a window paneduring opening and closing of the window pane in the door of a motorvehicle. The displacement areas can basically be divided into threeareas, Area A reaches from the fully opened window pane to a window paneclosed by a third. Area B extends from the window pane closed by a thirdup to shortly before the window pane enters the window seal. Area Cextends over the sealing area.

For an anti-jam protection there are basically two areas B and C whichare relevant during closing of the window, while in area A, as a resultof the large distance between the upper edge of the window pane and thedoor frame, the jamming of larger parts of the body can be ruled out.However, area A can also be included in the monitoring and control foran anti-jam protection.

In the area part B when a jamming state exists, it must be ensured thatthe force acting on the jammed object or the jammed part of the bodymust not exceed a certain predetermined amount and the lifting andlowering of the window must be guaranteed against motion resistances ofthe window lifter system, and where applicable, external influences. Inthe area part C, special conditions apply since here, as a result of theincreased resistance when the window pane runs into the seal, on the onehand a secure closing of the window pane must be ensured, and on theother for safety reasons a 4 mm bar must be recognized and reliablydistinguished from the influences of the displacement forces in thesealing area.

When establishing the displacement forces required for opening andclosing, for example, a window lifter system in addition to externalinfluences such as surrounding temperature, resistances when travelingover the displacement path, temperature of the displacement motor, etc.,of particular importance is the motor characteristic line of thedisplacement motor whose characteristic line is subject to considerablespecimen variations.

FIG. 2 shows, by way of a diagrammatic example, the motor characteristicline of two different electric motors which collect up different motorcurrents to reach a matching motor torque M. For a position-dependent“normal” torque M1, the one electric motor with the motor characteristicline MK1 requires a position-dependent “normal” lift current I*₁. Whereapplicable, the “normal” lift current is balanced by the influencingfactors. Another electric motor with the motor characteristic line MK2requires a position-dependent lift current I₁.

In the event of a maximum permissible torque M₂, the one electric motorwith the motor characteristic line MK₁ requires a maximum permissiblecurrent I*₂. The other electric motor with the motor characteristic lineMK₂ collects a maximum permissible current of I₂. Dependent on therelevant motor characteristic line of the electric motor used, accordingto the subject of the present invention, the excess force which isproduced from the difference between the maximum permissible torque andthe position-dependent normal torque is reduced to a predeterminedvalue, which must not be exceeded anywhere in the displacement path.

Upon reaching the set or calculated maximum current value whichcorresponds to the relevant maximum permissible torque or the maximumpermissible displacement force, the current collection of the electricmotor is restricted by a corresponding switch element, whereby themaximum motor torque and thus the maximum excess force of the windowlifter system shown in this embodiment is restricted.

FIG. 3 shows, in a block circuit diagram, a circuit arrangement forimplementing the method according to the invention in the case of awindow lifter displacement system as the electrically operated assemblyfor displacing a window pane 1 by means of a setting device 2 in theopening area of a motor vehicle door 3. The setting device 2 is drivenby an electric motor 4 in two directions of movement. The electric motoris fed through a switch device 5 from a voltage source 6 wherein, in theillustrated embodiment, the current direction through the electric motor4 can be changed by reversing the poles of the voltage source 6 throughthe switch device 5. For example, by arranging semi-conductor elementsin the bridge circuit and by arranging corresponding control of thesemiconductor elements lying in a bridge branch, the direction throughthe electric motor is changed.

The switching device 5 can consist of any semiconductor switch elementssuch as transistors (MOSFETs), thyristors as well as controllableresistors. The control of the switch device takes place through acontrol and regulating electronics device 7, which preferably consistsof a micro processor which is connected to a random accessory memory 8.The micro processor is additionally connected to an operating element 9as well as, where applicable, to a sensor device 10 which comprisessensors connected to parts of the displacement system. The sensor devicedetects other external influences, and can, where applicable, detect andmonitor the supply voltage.

The control and regulating electronics device 7 controls the switchdevice 5 in a way where the motor current is pulse-width-modulated inone or both flow directions so that the arithmetic mean value or thequadratic mean value (effective value) of the motor current can beinfinitely varied.

The control signals are delivered by the control and regulatingelectronics device 7 to the switch device 5. The control signals controlthe motor current in a way where in the area parts B and C according toFIG. 1, as well as where applicable in the area part A, an excess force,whose size is restricted by the control and regulating electronicsdevice 7, is imprinted on the displacement force. The displacement forceis required for displacing the setting device 2 and is generallydependent on the location of the lifting path. Without the excess force,to which the excess current or the excess torque of the electric motor 4corresponds as a difference of curves a and b of FIG. 4, the electricmotor 4 would exert on the setting device 2 only just enough force sothat the setting device 2 executes a lifting movement over apredeterminable displacement area.

The displacement force selectively takes into account the counter forcesappearing over the displacement area or a part of the counter forces.The excess force contains a force reserve to overcome a part of theadditional counter forces whose overall amount is restricted.

The excess force can thereby have a different restriction in thedifferent area parts of an overall displacement path. In area part C,for example, the excess force can be restricted to a higher quantityvalue than in area part B in order to overcome the additional resistancevalues in the seal area which are dependent on external influences, andto ensure a safe movement of the window pane into the seal area.

The displacement force curve can be determined by computer, empiricallyor preferably by means of a test run. The test run can thereby becarried out, for example, on the assembly belt prior to installing thevehicle door in a motor vehicle. The test run takes into accountindividual scatterings of the drive motors as well as of the movableparts of the electrically operated assembly and the resistance forceswhich occur during a lifting movement.

A measuring curve shown diagrammatically in FIG. 4 and which representsthe current collected by the displacement motor or the torque deliveredabove the lifting position, shows with a lifting position s1, the startof the window pane at the lower stop, with a lifting position s2, thebeginning of the window entering into the upper window seal, and with alifting position s3, the stop of the window pane against the upper doorframe.

From normal curve a, determined over a window lifter stroke through astandardized run for the current collection of the electric motor, therelevant maximum value of the permissible excess force is fixed by anenvelope curve b. The envelope curve is calculated by including variousinfluencing factors as shown in FIG. 4. These influencing factorsinclude the nominal speed of the electric motor, the operating voltage,the preliminary resistance in front of the electric motor, the motor andsurrounding temperature, as well as the aforesaid motor characteristicline. This envelope curve restricts the excess force over the entirewindow lifter stroke or over a predetermined partial area to at leastless than 100 Newton.

If the current of the electric motor, during a lifting movement of thewindow pane, reaches the fixed or calculated maximum value of thecurrent value corresponding to the excess force, then the current isrestricted and kept constant. This is achieved, for example, through acorresponding control of the switch device in the case of a pulse widthmodulation through a constant pulse duration/pulse pause ratio. Ifduring a lifting movement, the window pane is located completely in theupper seal, then independently of whether the current corresponding tothe maximum excess force was already reached and restricted in the sealarea, the full excess force can be reached on the window pane throughdelivery of the maximum permissible current according to curve b in FIG.4.

The method according to the invention allows, in a simple way, theresulting (maximum) excess force during operation of the window lifterto be adapted to heavy going areas (areas of operational difficulty)and/or heavy going (operational difficulties) in the seal inlet. To thisend the current is recorded in dependence on the lifting position duringeach operation of the window lifter system. For example, in the case ofa predetermined number of values of the current which correspond to themaximum excess force in the relevant lifting position, the current valuecorresponding to the normal displacement can be raised. In the same way,for example, friction values, which reduce during operation the amountof excess force dependent on the lifting position, can be adaptivelyreduced by correspondingly reducing the position-dependent excesscurrent.

FIG. 5 shows diagrammatically the path of the motor current or motortorque in dependence on the displacement path s or displacement time twith a boundary value regulation emphasized on a large scale in orderthat the method according to the invention may be explained andillustrated more clearly. This boundary value regulation takes placeover a path section Δs over a displacement time interval Δt. Theboundary value regulation can be produced for example through a dynamicinfluence, such as a pothole, a transverse groove, a slight heavy goingin the displacement area or the like. In the predetermined time intervalΔt, which starts when the motor current I reaches for the first time theboundary value predetermined by the envelope curve b and its duration ispredetermined as fixed, the motor current is regulated, for example, inpulse width modulation to a constant maximum value predetermined by theenvelope curve b. In this boundary value regulating area, in thepresence of a temporary dynamic counter moment, the electricallyoperated assembly is moved with a reduced speed.

At the end of this time interval Δt, the decision is made by the systemwhether or not to reverse the closing movement or stop the drive. Thedecision on a switch-off criterion becoming active up to reversing orstopping the system is made time-delayed, for example, after a length of200 ms. It can thereby be satisfactorily differentiated whether there isactually a jammed state or a temporary disturbance acting on the system,for example, as a result of traveling over a pothole. In this timeinterval the motor current is pulsated so that the predetermined maximumvalue is not exceeded. The electrically operated assembly delivers aconstant force of, for example, less than 100 Newtons so that even withthe appearance of an actual jammed state, no inadmissible high forcescan arise.

With extremely high-speed motors, it is thereby theoretically possiblehowever that the rotation energy stored in the motor armature is sogreat that the slowing down effect of the motor leads to temporarilyexceeding the force limit, for example the 100-N-limit. This rotationenergy is like the kinetic energy of the electrically operated assembly,such as a window pane broken down against the earth acceleration,against the friction and through deformation of an obstruction such as,for example, a jammed part of the body, or a force measuring cylinder.

Through a very short counter control over a period of, for example, 5ms, the motor can be stopped in a defined manner before the boundaryvalue (envelope curve b) is reached. The method described above can thenbe applied again.

The regulating method shown diagrammatically in FIG. 5 will now beexplained in further detail with reference to three different casescenarios.

FIGS. 6a and 6 b show in a diagrammatic illustration of the motorcurrent or motor torque over the displacement path (FIG. 6a) as well asover the displacement time (FIG. 6b) in the case of a “hard jam.” Ahard-jam is the jamming of an object or part of the body with immediatestandstill of the electrically operated assembly. In this case, the pathsection covered after reaching the predetermined boundary value of themotor current, which corresponds to the maximum value of the excessforce, amounts to Δs=0. The motor current regulation to thepredetermined boundary value through pulse width modulation leads to nofurther displacement of the electrically operated assembly, although theregulation takes place over the time interval Δt⁰. After this timeinterval Δt⁰ of, for example, 0.5 seconds, the drive device is switchedoff. Where applicable, the drive device is additionally reversed whenthe electrically operated assembly is located in the safety area.

For the case of the “soft jam” or the state of heavy going in thedisplacement area shown in FIGS. 7a and 7 b, a pulse width modulation tothe predetermined boundary value is undertaken when the motor currenthas reached this boundary value which corresponds to the maximum excessforce and is predetermined by the envelope curve. This boundary valueregulation taking place over a time span Δt¹ leads to a reduced speed ofthe electrically operated assembly which covers the displacement sectionΔs in this interval. Only when the electrically operated assembly comesto a complete standstill after the time interval Δt¹, or its speed dropsbelow a fixed boundary valve, is the switch-off criterion initiated.That is, after the time interval Δt¹, a boundary value regulation isundertaken over the predetermined time period Δt⁰.

FIG. 8 shows, on an enlarged scale, the case illustrateddiagrammatically in FIG. 5 of an outside dynamic influence, such as, forexample, what can occur through a pothole, a transverse groove or aslight heavy going in the displacement area.

In this case, during continued displacement of the electrically operatedassembly, a pulse width modulation of the motor current is carried outafter reaching the predetermined boundary value. The switch-offcriterion is not initiated, despite the current reaching the boundaryvalue or the envelope curve representing the maximum excess force,because neither the electrically operated assembly stands still nor doesthe speed fall below a predetermined boundary speed.

Upon reaching a current value corresponding to the maximum excess force,the current value corresponding to the resulting or maximum excess forceis kept substantially constant and after a fixed time span Δt⁰, thedrive device is switched off or reversed time-delayed.

If the current value corresponding to the maximum excess force isreached, unlike the known anti-jam protection method it is not assumedhere that this is a jammed state. Instead the displacement force or theexcess force is preferably restricted according to the measure of anenvelope curve. A parameter proportional to the displacement force, suchas, for example, the current collected by the drive device of theelectrically operated assembly or the torque delivered by the drivedevice, is regulated upon reaching a predetermined boundary value of thedisplacement or excess force. In this regulation phase, aparametercorrelated with the dynamics of the setting device of the electricallyoperated assembly, such as the speed or acceleration of the displacementdevice or assembly, is monitored and, depending on the behavior of theassembly, for example, further closing or lifting movement is continuedor there is control and regulating action of the drive device, forexample, the drive device is stopped or reversed. Reversing is carriedout, for example, in a displacement area wherein the window opening is,for example, more than 4 mm. Reversing the motor can be dispensed withand instead a motor stop with reduced moment can be provided if, forexample, the window opening is less than 4 mm or the window pane hasreached the area of the lower stop.

Basically it is possible to dispense with reversing if, in particular,it is not possible to differentiate with certainty between a seal inletand a jammed state, since according to the invention, the clamping forceacting on a jammed part of the body or an object is always smaller thanthe force leading to injury.

Time-delayed reversal, makes it possible to screen out dynamicdisturbances which can occur, for example, through temporary negativeaccelerations on traveling over potholes or through temporarydisturbances in the window lifter stroke. During the delay, the switchdevice is controlled by the control electronics so that the electricmotor delivers a constant torque to the setting device, that is thewindow lifter mechanism.

In many cases, it is expedient to restrict the rise of the motor torquein order, for example, to prevent a hard jam. By restricting the rise ofthe motor torque, the predetermined resulting excess force of the windowlifter rises very slowly. This can be produced, for example, byrestricting the current rise (di/dt).

With the solution according to the invention it is possible to meet eventhe most stringent anti-jam protection conditions with regard to a highrate of error of the measured value recorder (e.g. 65 N/mm).Furthermore, the solution according to the invention ensures a betterfunctioning in the case of a soft stop (before the lower stop) and witha smooth inlet (seal inlet with reduced excess force).

The envelope curve is, for example, adapted or calculated in dependenceon the operating voltage, the position of the motor characteristic linein the scatter field, the actual motor speed (motor current), the motorvoltage and the motor and surrounding temperature. Furthermore, changesin the displacement forces over the service life are taken into accountand the envelope curve is constantly updated.

During operation, the displacement motor gets only so much current thatit cannot do more than is predetermined by the envelope curve b. It isthereby possible to dispense with a reversing function in the area ofthe seal path, since as a result of the restriction on the excess forcewhen a thin object (e.g. a finger) is jammed, acute danger does notarise. Thus it is no longer necessary to differentiate between a jammedcase and heavy going of the system.

Instead of regulating the scanning ratio of the pulse width modulation,by means of evaluating the motor current by including the motorcharacteristic line, the ideal values for the pulse width modulation canbe calculated from the idling and actual speed of the electric motor byincluding the motor characteristic line so that no motor currentmeasuring is required which would require extra devices and thus costs.FIG. 9 shows diagrammatically a method of determining the scanning ratioof the pulse width modulation control by displacing the motorcharacteristic line so that a predetermined excess force is set.

Calculating the pulse width modulation values is only carried out bymeans of the idling speed and the actual speed of the motor followingits motor characteristic line. In FIG. 9 the speed n is entered over thetorque M and produces a motor characteristic line MK which ischaracteristic for the electric motor. The line is sufficient for astraight line equation. The intersection with the ordinate of theco-ordinate system is the idling speed n₀, wherein the torque is M=O.The intersection with the abscissa produces the torque M_(B) wherein themotor speed is n=0. With the rise A=n₀/M_(B) of the characteristicstraight line, the following arises for intermediate values of the speedn: $n_{1,2} = {n_{0} - {\frac{n_{0}}{M_{B}}*M_{1,2}}}$

If the jamming force is restricted to a value which is equal to thetorque M₂ belonging to the speed n₂, then the straight line MK′,displaced to the zero point of the co-ordinate system parallel to thestraight line MK, is produced whose intersection with the ordinate isthe idling speed n₀′. Line MK′ intersects with the abscissa at theboundary moment M_(B)′ and has a pitch of A=n₀′/M_(B)′ Interposedtorque/speed values are produced for$n_{1,2}^{\prime} = {n_{0}^{\prime} - {\frac{n_{o}^{\prime}}{M_{B}}*M_{1,2}}}$

When n₂′=0, then$n_{0}^{\prime} = \frac{n_{o}^{\prime}}{M_{B}^{\prime}}$

as well as at$M_{2},{n_{0} = {{n_{2} + {\frac{n_{0}}{M_{B}}*M_{2}}} = {n_{2} + {A*M_{2}}}}}$$M_{2} = \frac{{no} - {n2}}{A}$$\frac{n_{o}}{n_{o}^{\prime}} = {\frac{n_{2} + {A*M_{2}}}{A*M_{2}} = {{\frac{n_{2}}{A*M_{2}} + 1} = {\frac{n_{2}}{n_{0} - n_{2}} + 1}}}$

As a result of the proportionality between the speed n and the motorvoltage U, which is in turn proportional to the scanning ratio of thepulse width modulation, the following arises:${\frac{{PWM}_{alt}}{{PWM}_{neu}} = \frac{n_{0}}{n_{o}^{\prime}}};{{PWM}_{neu} = \frac{{PWM}_{alt}*\left( {n_{o} - n_{2}} \right)}{n_{o}}}$

For a speed n₃ at the restriction straight lines, thus applies

n₃′=n₀′−A*(M₁+ΔM)=n₀−n₂−A*(M₁+ΔM)

If the motor is moved further after the voltage reduction, (set excessforce) then after a predetermined time of, for example, 200 ms, it isoperated again at full power. If the motor remains stationary for thistime however, this signifies a jammed state and the polarity of themotor is changed, that is the electrically operated assembly isreversed. The sensitivity to vibrations is improved and the jammingforces are reduced.

Since the motor stops when the matching values are exceeded, the resultis irregular running of the electrically operated assembly, in the eventof heavy going. In order to prevent this, an adaptive system describedabove is provided which learns the positions of the heavy going areasand stores them. When running over these areas, the matching forces(envelope curve) are increased and thus the irregularities arecompensated.

What is claimed is:
 1. A method for electric control and regulation ofmovement of an electrically operated assembly of a motor vehicle, theassembly having a setting device which is connected to a drive device,and a control and regulating electronics device, the method comprising:restricting at least in a partial area of a displacement path of theelectrically operated assembly, a displacement force of the electricallyoperated assembly to a predetermined boundary value dependent on thedisplacement path, regulating a first parameter proportional to thedisplacement force of the electrically operated assembly, upon reachingthe predetermined boundary value, to a first parameter valuecorresponding approximately to the boundary value; monitoring a secondparameter correlated with a dynamic of the setting device during aregulating phase; evaluating the second parameter in the control andregulating electronics device; generating a control and regulatingaction for the drive device; and delaying at least one of aninterruption of current delivered to the drive device and a change ofrotary direction of the drive device by a time interval; wherein thetime interval is measured so that a satisfactory differentiation can bemade between a lammed state and an external temporary dynamicdisturbance.
 2. The method according to claim 1 wherein the regulatingstep includes regulating the first parameter, that is proportional tothe displacement force, to the first parameter value correspondingapproximately to the predetermined boundary value dependent on thedisplacement path, wherein the first parameter corresponds to a maximumpermissible excess force at a relevant displacement position, whereinthe maximum permissible excess force is a force which exceeds a forcerequired for displacing the setting device.
 3. The method according toclaim 1 or 2 wherein the regulating step includes regulating the firstparameter to the first parameter value corresponding approximately tothe predetermined boundary value within a predetermined time span untilthe first parameter falls below the predetermined boundary value.
 4. Themethod according to claim 1 wherein the regulating step includesregulating the first parameter to the first parameter valuecorresponding approximately to the predetermined boundary value untilthe setting device or the drive device has come to a standstill.
 5. Themethod according to claim 1 further comprising delivering, through thedrive device during the duration of the delay, a constant torque to thesetting device.
 6. The method according to claim 1 wherein the firstparameter corresponds to a current supplied to an electric motor of thedrive device.
 7. The method according to claim 1 wherein a slope of acurrent collection of an electric motor is at least one of delayed andrestricted.
 8. The method according to claim 1 further comprisingholding the first parameter constant during the delaying of at least oneof the interruption of current delivered to the drive device and thechange of rotary direction of the drive device by the time interval. 9.A method for electric control and regulation of movement of anelectrically operated assembly of a motor vehicle, the assembly having asetting device which is connected to a drive device, and a control andregulating electronics device, the method comprising: restricting atleast in a partial area of a displacement path of the electricallyoperated assembly, a displacement force of the electrically operatedassembly to a predetermined boundary value dependent on the displacementpath, regulating a first parameter proportional to the displacementforce of the electrically operated assembly, upon reaching thepredetermined boundary value, to a first parameter value correspondingapproximately to the boundary value; monitoring a second parametercorrelated with a dynamic of the setting device during a regulatingphase; evaluating the second parameter in the control and regulatingelectronics device; generating a control and regulating action for thedrive device, wherein the regulating step includes regulating the firstparameter to the first parameter value corresponding approximately tothe predetermined boundary value within a predetermined time span untilthe first parameter falls below the predetermined boundary value;increasing the predetermined boundary value of the parameter by apredetermined amount when the setting device or the drive device isbrought to a standstill; and within the predetermined time span,delivering a control impulse by an operating device which causes aclosing of the electrically operated assembly.
 10. A method for electriccontrol and regulation of movement of an electrically operated assemblyof a motor vehicle, the assembly having a setting device which isconnected to a drive device, and a control and regulating electronicsdevice, the method comprising: restricting at least in a partial area ofa displacement path of the electrically operated assembly, adisplacement force of the electrically operated assembly to apredetermined boundary value dependent on the displacement path,regulating a first parameter proportional to the displacement force ofthe electrically operated assembly, upon reaching the predeterminedboundary value, to a first parameter value corresponding approximatelyto the boundary value; monitoring a second parameter correlated with adynamic of the setting device during a regulating phase; evaluating thesecond parameter in the control and regulating electronics device;generating a control and regulating action for the drive device, whereinthe first parameter corresponds to a current supplied to an electricmotor of the drive device; delivering a pulse width modulation of thecurrent to the electric motor at least in a regulating area; andregulating a value of the current to a boundary value dependent on thedisplacement path and to correspond to the maximum permissible resultingexcess force.
 11. The method according to claim 9 further comprisingpredetermining the effective value of the current based on at least oneof a motor voltage, a motor speed, a the motor temperatures, and a thesurrounding temperature.
 12. The method according to claim 9 furthercomprising reversing poles for a temporary defined braking of theelectric motor by reversing the current supplied to the electric motor.13. The method according to claim 10 wherein one of a maximum peakvalue, an arithmetic value and a quadratic mean value is regulated tocorrespond to the maximum permissible resulting excess force.
 14. Amethod for electric control and regulation of movement of anelectrically operated assembly of a motor vehicle, the assembly having asetting device which is connected to a drive device, and a control andregulating electronics device, the method comprising: restricting atleast in a partial area of a displacement path of the electricallyoperated assembly, a displacement force of the electrically operatedassembly to a predetermined boundary value dependent on the displacementpath, regulating a first parameter proportional to the displacementforce of the electrically operated assembly, upon reaching thepredetermined boundary value, to a first parameter value correspondingapproximately to the boundary value; monitoring a second Parametercorrelated with a dynamic of the setting device during a regulatingphase; evaluating the second parameter in the control and regulatingelectronics device; generating a control and regulating action for thedrive device, wherein the first parameter corresponds to a currentsupplied to an electric motor of the drive device; classifying anelectric motor in a test station with regard to at least onecharacteristic feature; and calculating the predetermined boundaryvalues, that depend on the displacement path and which form the envelopecurve restricting the excess force, from the characteristic feature. 15.The method according to claim 14 further comprising adaptively changinga path of the envelope curve by detecting and storing positions ofdecelerations of the electrically operated assembly.
 16. The methodaccording to claim 14 further comprising raising up the envelope curvethat restricts the excess force when one of a speed of the electricallyoperated assembly is not reduced after reaching the predeterminedboundary value through the first parameter and the negative accelerationdoes not exceed a boundary value.
 17. The method according to claim 16wherein the raising up of the envelope curve takes place by apredetermined amount.
 18. The method according to claim 16 wherein theraising up of the envelope curve takes place up until the speed of theelectrically operated assembly has reached a certain value.
 19. Themethod according to claim 14 wherein the at least one characteristicfeature is a slope of a motor characteristic line.
 20. The methodaccording to claim 19 further comprising associating the firstparameters of the motor characteristic line of the electric motor withdisplacement positions over the displacement path; storing the firstparameters of the motor characteristic line in the control andregulating electronics device; and calculating the envelope curverestricting the excess force based on these parameters of the motorcharacteristic line.
 21. The method according to claim 19 furthercomprising adding an amount of a current that corresponds to the maximumresulting excess force to a motor current of the motor characteristicline that corresponds to a relevant motor torque to sum to a resultingmaximum value of the current; and restricting the current supplied tothe electric motor over the at least one partial area of thedisplacement path to the resulting maximum value of the current.
 22. Themethod according to claim 19 further comprising calculating a scanningratio of a pulse width modulation from an idling speed, an actual speedand the motor characteristic line of the electric motor.